roofing contractors and stuff that blows up

Today I learned that during monsoon season, roofing contractors get behind upwards of a month, so your leak had better be able to wait. I have concluded, by standing on my kitchen counter and sniffing in the direction of the water mark on the ceiling, that there is not enough mold to worry about right now. The carpet is a bigger problem.

The carpet is a much bigger problem. The carpet reeks.

So, I'm going to keep reminding myself that a 30% chance of rain around here means a 30% chance of getting hit by it, and hopefully when it does rain on us again, it won't rain too hard.

Now, to properly appreciate the stuff that blows up, most of you need some background. In some branches of physics, we keep various materials and equipment very, very cold. Instead of using ice cubes, we use liquid nitrogen, which is -320 F (-196 C, 77 K), which we store in giant thermoses called dewars. The liquid is boiling in the dewars, so you have to have a blow off valve so the vapor can escape. If you keep a little pressure in there, it boils slower, so your stash of nitrogen lasts longer. If you keep the pressure too high, the dewar blows up. You can also blow one up by essentially breaking the thermos so your nitrogen gets too hot too fast. However, it's not that hard to keep the valves in good shape and not damage the dewar walls. I mean, they're steel.

Without further ado, here is an account of how not to handle a dewar, and here is one about dewar maintenance. All I have to say about these two stories is holy cow.